Field
The present disclosure relates to a wireless communication system.
Description of the Related Art
In recent years, there has been a system carrying out communication via a rotatable portion, such as an articulation portion of a robot arm, and a joint portion between a network camera and a camera platform. There has also been a system carrying out communication between two apparatuses connectable to each other in a plurality of different orientations, such as a communication cable for a mobile device supporting reversed insertion. When wireless communication is used for the communication in a system like such systems, an orientation of a reception antenna is changeable relative to a transmission antenna.
Japanese Patent Application Laid-Open No. 2016-29785 discusses a method for realizing high-quality communication by carrying out communication based on electromagnetic field using a transmission antenna and a reception antenna, each including two electrodes. More specifically, Japanese Patent Application Laid-Open No. 2016-29785 discusses a method for transmitting data by inputting a differential signal that is an electric signal of opposite phase into a first transmission electrode and a second transmission electrode included in the transmission antenna.
The communication can, however, be destabilized in a system carrying out the wireless communication between one antenna including a plurality of electrodes and another antenna including a changeable orientation relative to the antenna. For example, it is conceivable that efficiency of the communication is substantially changed according to the orientation of the antenna in a case where the electrode included in the one antenna and the electrode included in the other antenna face each other in some orientation, but do not face each other in a different orientation.